The number attribute of an MCAD document in the Windchill database is a string identical to the Creo Parametric file name of a document. If you change the number attribute of an MCAD document by using a mapping rule or altering the object when it is on the local disk, you create data that is incompatible with the assembly files that refer to it. Attempting to repair a number change by reverting to the original information does not succeed because the software perceives an attempt to check in the renamed object as an attempt to duplicate an existing object.